package com.filetransfer.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.server.support.DefaultHandshakeHandler;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.server.HandshakeInterceptor;
import org.springframework.http.server.ServletServerHttpRequest;

import javax.servlet.http.HttpServletRequest;
import java.util.Map;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/ws")
                .setAllowedOriginPatterns("*")
                .addInterceptors(new HandshakeInterceptor() {
                    @Override
                    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response,
                            WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
                        if (request instanceof ServletServerHttpRequest) {
                            ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
                            String ipAddress = getIpAddress(servletRequest.getServletRequest());
                            attributes.put("ip", ipAddress);
                        }
                        return true;
                    }

                    @Override
                    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response,
                            WebSocketHandler wsHandler, Exception exception) {
                    }
                })
                .withSockJS();
    }

    private String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        registry.enableSimpleBroker("/topic");
        registry.setApplicationDestinationPrefixes("/app");
    }
}